class_docstr: Test various VIIRS-specific composites.
class_docstr_tok: ["Test","various","VIIRS-specific","composites","."]
docstr: Return fake lunal zenith angle dataset for DNB tests.
docstr_tok: ["Return","fake","lunal","zenith","angle","dataset","for","DNB","tests","."]
code: def lza(self, area):
      """Return fake lunal zenith angle dataset for DNB tests."""
      lza = np.zeros(area.shape) + 70.0
      lza[:, 3] += 20.0
      lza[:, 4:] += 45.0
      lza = da.from_array(lza, chunks=25)
      c03 = xr.DataArray(
          lza,
          dims=("y", "x"),
          attrs={
              "name": "lunar_zenith_angle",
              "area": area,
              "start_time": datetime(2020, 1, 1, 12, 0, 0),
          },
      )
      return c03
  
file_path: satpy/satpy/tests/compositor_tests/test_viirs.py
imports: from datetime import datetime
  import dask.array
  import numpy
  import pytest
  import xarray
  from pyresample.geometry import AreaDefinition
label_desc: Use image node_id 4 for calling the TestVIIRSComposites obj's underlying member method code with example usage: obj.lza(area) and returns: c03